doc: use npm team for npm upgrades in collaborator guide

The collaborator guide suggests pinging individuals about npm upgrades.
Change to pinging the npm team instead.

PR-URL: #33999
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Gerhard Stöbich <deb2001-github@yahoo.de>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Andrey Pechkurov <apechkurov@gmail.com>

Author: Trott

doc/guides/collaborator-guide.md

@@ -745,7 +745,7 @@ may impact an LTS release.
 | upgrading c-ares                         | @rvagg                                                                |
 | upgrading http-parser                    | @nodejs/http, @nodejs/http2                                           |
 | upgrading libuv                          | @nodejs/libuv                                                         |
-| upgrading npm                            | @fishrock123, @MylesBorins                                            |
+| upgrading npm                            | @nodejs/npm                                                           |
 | upgrading V8                             | @nodejs/V8, @nodejs/post-mortem                                       |
 | Embedded use or delivery of Node.js      | @nodejs/delivery-channels                                             |